Backflow prevention for computing devices

Abstract

Embodiments of the invention are directed to methods and systems for backflow prevention for computing devices. In an embodiment, a system of sensors, processors, and airflow stimulation devices, such as fans, are used to prevent backflow of high temperature gasses through a server housing. The backflow of high temperature gasses may be a result of a pressure differential between a region in which cooling gases are disposed and a region in which high temperature exhaust gasses are disposed.

What is claimed is: 
     
       1. A method, comprising:
 in a server rack having computing devices arranged in a stack, determining that at least two of the computing devices are active and at least one of the computing devices is idle, wherein the idle computing device is disposed between the active computing devices and has a fan operating with reduced fan speeds compared to the active computing devices; 
 detecting an air temperature at a first region of the idle computing device; 
 detecting an air temperature at a second region of the idle computing device, wherein the first region is physically nearer an air inlet of the server rack than the second region, and wherein the second region is physically nearer an air outlet of the server rack than the first region; 
 determining that the idle computing device is in a state of backflow, wherein the state of backflow is created by an outflow of the active computing devices through the idle computing device; 
 calculating an air flow rate configured to counteract the backflow; 
 using the calculated air flow rate to increase a speed of the fan of the idle computing device in a direction opposite the backflow, and maintaining the increased fan speed until the idle computing device is power cycled; and 
 indicating that the backflow has been counteracted. 
 
     
     
       2. The method of  claim 1 , further comprising triggering an event in response to the determination that the temperature at the first region is higher than the temperature at the second region. 
     
     
       3. The method of  claim 2 , wherein the event is triggered in response to the temperature of the first region exceeding the temperature of the second region by a difference defined by a predetermined threshold. 
     
     
       4. The method of  claim 2 , wherein increasing the air flow is performed in response to triggering of the event. 
     
     
       5. The method of  claim 1 , wherein increasing the air flow comprises causing air to flow from the first region to the second region. 
     
     
       6. The method of  claim 5 , further comprising running the fan until a second event is triggered. 
     
     
       7. The method of  claim 6 , wherein the second event is the expiration of a predetermined period of time. 
     
     
       8. The method of  claim 6 , wherein the second event is the air temperature at the second region exceeding the air temperature at the first region by a difference defined by a predetermined threshold. 
     
     
       9. The method of  claim 1 , further comprising:
 monitoring the difference between the first region and the second region; and 
 increasing the air flow between the first region and the second region in response to a determination that the temperature at the first region has not reduced at a predetermined minimum rate. 
 
     
     
       10. The method of  claim 9 , wherein the rate of air flow is dynamically adjustable according to a dynamically adjustable speed of the fan. 
     
     
       11. A system, comprising:
 a first temperature sensor configured to detect a temperature at an inlet of a given server housing among a plurality of other server housings stacked within a rack, wherein each of the server housings comprises a respective computing device, wherein a given computing device in the given server housing is in an idle state, wherein at least two other computing devices in at least two other server housings are in an active state, wherein the given server housing is positioned between the at least two other server housings, and wherein the idle computing device has a fan operating with reduced rotating speeds compared to the active computing devices; 
 a second temperature sensor configured to detect a temperature at an outlet of the given server housing; and 
 a processing device having program instructions stored thereon that, upon execution, cause the system to:
 in response to a difference between the temperature at the inlet and the temperature at the outlet being positive, increase a rotating speed of the fan the given server housing relative to the speed of one or more fans of the at least two other server housings, and maintaining the increased rotating speeds until the idle computing device is power cycled. 
 
 
     
     
       12. The system of  claim 11 , wherein the program instructions, upon execution, further cause the system to identify a backflow event in response to the determination that the temperature at the inlet is higher than the temperature at the outlet. 
     
     
       13. The system of  claim 12 , wherein the program instructions, upon execution, further cause the system to identify the backflow event in response to a determination that the other two server housings are in a state of outflow. 
     
     
       14. The system of  claim 12 , wherein the program instructions, upon execution, further cause the system to increase the rotating speed of the fan in response to identification of the backflow event. 
     
     
       15. The system of  claim 14 , wherein the program instructions, upon execution, further cause the system to run the fan at the increased revolving speed only until a second event is triggered. 
     
     
       16. The system of  claim 15 , wherein the second event is the expiration of a predetermined period of time. 
     
     
       17. The system of  claim 15 , wherein the second event is the temperature at the outlet exceeding the temperature at the inlet by a difference defined by a predetermined threshold. 
     
     
       18. The system of  claim 11 , wherein the program instructions, upon execution, further cause the system to:
 monitor the difference between the inlet and the outlet; and 
 further increase the increased revolving speed of the fan in response to a determination that the temperature at the inlet has been reduced at a rate smaller than a predetermined minimum rate. 
 
     
     
       19. The system of  claim 18 , wherein the revolving speed of the fan is dynamically adjustable.